Two of the most common defects I find in kitchen plumbing are: 1) Installation of a flexible drain line, and 2) The dishwasher drain does not make a high loop underneath the kitchen sink. Correcting the dishwasher drain line is easy. Simply, attach the bottom of the hose up beneath the sink, so it loops up. This is to prevent potential back flow contamination of the dishwasher. The problem with the accordion pipe is the collection of goop, thereby allowing for clogs. Replacing the flexible drain line requires a little more plumbing skill, but if your a handy person, it is a relative snap.